I recently updated from 42.2 to 42.3 with great difficulty but got it done. Grub did not find my other installs as in the past. I have two disks with two versions of openSUSE and Windows (7 & 10) installed. How do I get the grub menu to find them?
Is it possible that your update switched you from legacy booting to EFI booting? Or from EFI booting to legacy booting?
Run YAST > System > Bootloader.
Or open a root terminal and type in grub2-mkconfig -o /boot/grub2/grub.cfg
I had to do this yesterday after an update disabled YAST. I’ve cleared that problem with help from a member here.
Vide “Update Disabled YAST.”
I seem to sense that it is something more along these lines, as well … especially since I note this in Prexy’s message:
updated from 42.2 to 42.3 with great difficulty
I think we need to know the answer to Neil’s question, and a few more details about the upgrade, especially concerning the “great difficulty”. Also, the answers to the other questions about the Yast Bootloader module.
Thanks for all the tips!
I got this sorted out. I tried running os-prober both as root and regular user but always got the “file not found” error. I had assumed that it was always part of an install. But to be sure, I looked it up in yast and found it was not installed. I used yast to install it. Then ran it as root. A reboot brought the grub menu back, showing each os on each disk. As I type this, I realize I didn’t test the menu to see if it actually loaded the other OS. I will test that now. If it doesn’t work, I’ll be back for help!
Fraser_Bell’s comment about “install with great difficulty” reminds me that I didn’t explain that. I first tried an online update from 42.2 but it failed because I was low on disk space. I tried different things to get an update but the installs either failed or, when it finally worked, deteriorated with each reboot. I gave up and did a full install with formatting the partition that 42.2 was installed on. I still have Windows 10 on that drive and Win 7 with 42.2 on the second hdd. To be clear, I blame the lack of disk space for my difficulty in installing 42.3, not openSUSE.
os-prober is normally in a default install not at all sure how it could have been missed.
Glad you got it sorted out 
… and that leaves me wondering what else might have been missed …